Assembling several integrated circuits required by a system in a single package is now a common practice for complex electronic systems, and is often referred to as system-in-package (SIP). A SIP assembly may contain digital, analog, mixed-signal, and often radio-frequency functions in a single package. For SIP applications, a multi-band antenna designed to transmit or receive different electromagnetic waves is applied for millimeter wave wireless communication, WiFi, and telecommunication, etc. However, there are many challenges related to such multi-band antenna.